As a rule, a chest x-ray is not useful in finding mesothelioma early. One test being studied is a blood test. This test measures the blood levels of certain substances that are higher in people who have mesothelioma. But right now blood tests are used mainly to follow the course of the disease in people who are already known to have mesothelioma.

Most of the time mesothelioma is found when a person goes to a doctor because of symptoms. Early symptoms can be very general and are often ignored. Most people with this type of cancer have symptoms for only a few months before the cancer is found.

Symptoms of pleural mesothelioma (lining of the chest) can include:

• pain in the lower back or at the side of the chest
• shortness of breath
• trouble swallowing
• hoarseness
• cough
• fever
• sweating
• tiredness
• weight loss
• swelling of the face and arms
• muscle weakness

Symptoms of peritoneal mesothelioma (lining of the abdominal cavity) include:

• belly pain
• weight loss
• nausea
• vomiting
• fluid or a lump in the abdomen (belly)

Of course, these same symptoms can also be caused by other problems. But if you have worked with asbestos and you have any of these symptoms, you should see a doctor right away.

If there is reason to think you might have mesothelioma, the doctor will ask you questions about your health and do a complete physical exam. The exam can help tell if you have fluid in the chest, abdomen, or heart. This fluid can be a sign of mesothelioma. Then one or more of the tests below can be used to find out whether you really have cancer.

Imaging tests

These tests allow the doctor to see a picture of the inside of your body. These tests might be done for a number of reasons, such as to help find an area that might be cancer, to learn how far cancer has spread, and to help learn whether treatment is working.

Chest x-ray: The x-rays might show thickening of the lining of the lungs or other signs of asbestos exposure leading to mesothelioma.

CT scans: A CT scan (also known as a CAT scan) is like an x-ray but it gives detailed cross-sectional pictures of your body. Instead of taking one picture, a CT scanner takes many pictures as it moves around you. A computer then combines these pictures into an image of a slice of your body.

CT scans are often used to help decide if you have mesothelioma and to help find the exact place of the cancer. They can also help find out much the cancer has spread.

Often after the first set of pictures is taken, you will get an intravenous (IV) injection of dye that helps better outline parts of your body. A second set of pictures is then taken. Some people are allergic to the dye and get hives, a flushed feeling, or, rarely, more serious problems like trouble breathing and low blood pressure. Be sure to tell your doctor if you have ever had a problem from any dye used for x-rays.

CT scans take longer than regular x-rays, and you need to lie still on a table while they are being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that goes around the table.

PET scan: A PET scan uses glucose (a form of sugar) that contains a radioactive substance. Cancer cells in the body absorb large amounts of the radioactive sugar and a special camera can find the radioactivity. This test can help tell whether a thickening of the tissues is cancer or just scar tissue. It can also show the spread of cancer. Some newer machines are able to do both a PET and CT scan at the same time.

MRI scans: This test uses radio waves and strong magnets instead of x-rays to take pictures. The energy from the radio waves is absorbed and then released in a pattern formed by the type of tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of parts of your body. MRI scans may be useful in looking at the thin band of muscle below the lungs that is responsible for breathing (the diaphragm). Mesothelioma can spread there.

A contrast material might be injected just as with CT scans. MRI scans take longer than CT scans -- often up to an hour. Also, you are placed inside a narrow tube, which is confining and can upset people with a fear of enclosed spaces. The machine makes a thumping noise, and some places will give you headphones with music to block out the noise.

Blood tests

Blood levels of certain substances are often high in people with mesothelioma. Thus far, blood tests have proven more useful in people who already have mesothelioma to follow their progress during and after treatment.

Other blood tests will be done to check the blood cell counts and levels of certain chemicals in the blood. These tests can give the doctor an idea of how much the disease has spread, and how well organs such as the liver and kidneys are working.

Tests of fluid and tissue samples

Fluid or tissue samples may be taken from the chest, stomach, or heart area with a needle and sent to the lab to see if cancer cells are present. This is known as a biopsy. It may be done in different ways, depending on where the cancer is thought to be.

If you have fluid build-up that may be from mesothelioma, a sample of this fluid can be removed by putting a long, hollow needle through the skin, into the fluid, and removing it. Numbing medicine is used on the skin before the needle is put in. The fluid is tested to see if there are cancer cells in it.

This test has different names depending on where the fluid is:

• Thoracentesis removes fluid from the chest cavity.
• Paracentesis removes fluid from the abdomen (belly).
• Pericardiocentesis removes fluid from the sac around the heart.

Other methods of looking inside the body involve making small cuts (incisions) in the chest or stomach area and then using a long, narrow, lighted tube with a video camera to look directly at the area in question. Using this, the doctor can see places where there might be cancer and take out small pieces of tissue to look at under the microscope. The doctor can also take out lymph nodes and fluid and look to see whether a tumor is growing into nearby tissues or organs.

In another approach, the doctor can put a lighted tube through the mouth and into the chest. This is called a bronchoscopy. If the tube is placed through the skin and under the chest bone, and then moved down into the chest, it is called a mediastinoscopy.

Surgery: Surgery allows the doctor to remove a larger sample of tumor or, sometimes, the whole tumor.

Testing the samples in the lab

No matter which approach used to get them, biopsy and fluid samples are sent to the pathology lab. There, a doctor will look at them under a microscope and do other tests to decide whether cancer is present (and if so, what type of cancer it is).

It is often hard to tell it is mesothelioma by just looking at the cells (or even tissue) from the fluid around the lungs, stomach, or heart. So other lab tests may be done, too.

Pulmonary function tests

Pulmonary function tests (PFTs) may be done after mesothelioma is found to see how well your lungs are working. This is important if you might have surgery because taking out part or all of a lung means your lungs will not hold as much air. It is important to know how well the lungs are working before the surgery. These tests can give the doctor an idea of how much lung can safely be removed. For PFTs, you breathe in and out through a tube that is connected to different machines.

Last Medical Review: 04/01/2009
Last Revised: 04/01/2009